#include<stdio.h>

double a3, a2, a1, a0;
double f(double);

int main()
{
    double a, b;
    scanf("%lf %lf %lf %lf",&a3, &a2, &a1, &a0);
    scanf("%lf %lf",&a, &b);
    if(f(a)*f(b) < 0 && b-a >= 0.0001)
    {
        while(f((a+b)/2.0) != 0)
        {
            if(f((a+b)/2.0) * f(a) > 0)
            {
                a = (a+b)/2.0;
            }
            else if(f((a+b)/2.0) * f(b) > 0)
            {
                b = (a+b)/2.0;
            }
            if(b-a<0.0001)
            {
                break;
            }
        }
        printf("%.2f",(a+b)/2.0);
    }
    else if(f(a) == 0)
    {
        printf("%.2f",a);
    }
    else if(f(b) == 0)
    {
        printf("%.2f",b);
    }
    else if(b-a<0.0001)
    {
        printf("%.2f",(a+b)/2.0);
    }

    return 0;
}

double f(double x)
{
    double y;
    y = a3*x*x*x + a2*x*x + a1*x + a0;
    return y;
}